Slide fastener



Oct. 13, 1953 G H RAKOwn-ZKY 2,654,930

I SLIDE FASTENER Filed Aug. 17, 1949 INVENTOR.

Patented Oct. 13, 1953 iran smms PATENT or eier;

Gnemrfmnakwmhy, Kinwenunmmfm; lim

Rakowitzkxsaninistrator of said Gregor H.

mawitukx, `decease Myiinverrtinreiateseto a'slidee fastener mountiedi stringersi and@ manipulated by. means off a slide:

objectv` oftheinventionisto4 provide a siidefastener that does not requirei as closeia machining toierance.- as-` the present ball and socket? type' of slide fastener.

Atmiiliecrl obj'eti off the invention is*` to" provide a slide fastener" theel'ements forming tiieletener' are-iterengaged with a' clearance therebetween when tliefasteneris closed; i-"tiir'tlierobject of'thednvention isto provide a` slide vi'iusiiener havingtheiappearance ofa solid metal unit when the fastener is closed.l

Ai stili1 further objectI the invention is= to make 7*the :elements-attachedfto one stri-nger to yengage the` StringerY ofxf'tieopposite--elemerits` when the i'atilenei'w isfclosed:

T-hoperationoI-thefastener-is based-on mov--Y anguiariy in= oppositefdii'eetioni byi means" of aiV slide; proximatefastenereiexirentaV eachelementfhavinig surfaceL curvatures 'that interengage with a: clearaneertherebetweerr in normal closed position.`

Any attempt-'to sefiarate the elements without ai slide is prevented either-f byfinterengagement :if-elements'` with thebead=of"the opposite Stringer Orriyv the abutment' 0I the'curved sur-facesofjadjitcteiltelements'` or both; Y

l'n thewappendedf drawing forming part .of `this applications A Figure 1iv is ab elevation `of the `fas-- tener;v the slide,v beingshown in" section;

f Figure"2is a-magni-iiedelevation ot `a section of fastenerclosed'; i

Figure 3`1is a similar` elevation ai-hoirin'g-H the maximum disglacement of the elements`- inthe closedL position ofv the` fastener;

Figure 4.. is a.. sectiomondineJ-l, Figure. 1;

Figure is a plan view ofthe convex surface of the elenieiits;`

Fiurez is an end elevation of the e1ement; and

Figure-,'13 is asectonpn lineg-lf-g Figure 5:

Ri'efeisrinarto.A the, drawings.; n

"Iiheffastener` elements, IIL aref-al1 aiilm: each haring af; rectanguiar-A contour; formedfi;A by.;AV sides Iaii'and ends, Il.. Thetop Iiwamgbottoxn; |14I are convex and concave-,respectivelnand of the same cylindrical curvature. So that the ends I2 are of lesserthickness than the'middle of the elements? asi-best shown--in Figure 'Zi Each eien'nentL has opposite end--cut-outsls-and llt*respactively: first for clamping the element to the edge bead I1 of the Stringer I8, and the other cut-out I6 accommodating the bead of the opposite Stringer 2'] i Y I whenntneriastenernis closed: The.elementi',Innere;-` fore` im anarched` mate;`

The endv walls I 9^: and 20 .i of?. the; cut-outs; I5, and Mii` are'. perpendicular to the! planev inswhich bottoni edgesf- ZI-i ci? trie-raton lie: Theilengtmof the` spambetween. the edges:` 211 isA greater than the radius of curvatura oitheicylin'dricai' surface ofthe elexnenI-.i-y` and maybeexpressedf as BMGS. TheA width off the: element. Il ie'sslsthan, the lengthl or the@ span; butitiiasum'cientlto provide walls on the side of cut-out I6 strongzelmug to resist lateral shear. The ratio of therwidth oithe` elements: to the lengtlr1 oi'theispan about 3. tof-42 shown. Figure: i, twouoppositegstringers I8; each provided. ivi-tit` spaced elements; Inl on each: i beadr IIT thereon, are? engaged'. by"` aA slide. 22e The distance. between the: elements:` im on the same bead, that is;.betwee`rn the-.convex anda' ccmcaife surfaces@ off adjacent. ei'ements`` I uz'. equals the thickestfpact ofrtheeiementplus theA clearance 23 provided: between the; adacent. elements. on opposite: beadsz when. the fastener' closed, as shown in:;}ig.urei2;` The thickest parixofil thefeie'- niente.` |0 -liesfinrplanef pemendicul'an tthe span andfl contains elementsof? eachi cylindricaisur@ face. The.` ratio; ofi' the thickest-parti to@y thattof thearadiusfof; curva-turcas; ktoz. Withithe added clearanceL 233 provided; to; each; convex. amtcone caweisurfaceiof;.amelementsthdlsunnmay `he ex,- pressed as a ratiz'to, theramliusuoizfcurvatureas Lto Therefore; 9.1c1earanceats thescentrai portion ci supereimposed; arcuated elements 4isi-equal tous of thezzrazdius of;v curvaturesof` theselement When: azfas-tener off construction? is closed: aa shownxirr 2; the i clearance'-` 23:v between element permits;A a relative longitudinal movement fof-zth'e felementsiconnectedrtothe opge# site beadsizof; thegstringers.. Thisv displacement-is arrested by;- the engagement ofr .the edges; l-.I of thesparr of. eachV elementi with .the corresponding convexizsurfcefoff therprmeimateI e1ement',i,so=\that eachlement: Iznfacts rassen-abutment limitinggthe longitudinali dispiacemerinof"y the elementsias: in dioatelti's` Thehrelative distancee thmeiements IB move whenjinzciosedepositiom aszshowneinwiiaure 3, may be expressed in a ratio;` togthefradiuafa-s about?V 11 tof' 7i Itis` maid-mum. dispiacementigin closed' position-shows .infBigure--Lthatthev moi: liody` portion'` of.` thea head2? Iltf off` th'ei` st'ringcrfI t8 remainsstraddiecuby lthe cut-vout- Iir'ofi'theseiea menta I l thus AJin'eventing separtiioii: in thet lati; eral direction or transverse to the curvature of the elements.

The opening and closing of the fastener by the slide 22, as illustrated in Figure 1, do lnot differ from the present type of ball and socket fastener.

It Will be noted that in my fastener the elements I0 do not interlock normally when the fastener is closed, as shown in Figure 1. The elements I0 of the fastener are spaced by the clearance 23 as previously explained. This arrangement permits the manufacture of the elements Y and the'ir'assembly with machine tolerance not as close as required in the manufacture of ball and Socket type of slide fastener. Furthermore, the Y tooling and number of operations required in the manufacture of my slide fastener are less costly and exacting than the present balland socket fastener. i l Y i In the element of the fastener, the curved surfil face extends through its entire top and bottom areas, andthe fastener elements are superimposed When the fastener is closed by their slide to present a substantially co-Vaxial unit of spaced fastening elements Vin the normal position, as shown in Figure l. The elements of the fastener are superimposed'with a clearance therebetween, and it is only when a limited movement is attempted by pulling on the stringers to separate them that the clearance isdeformed in the fastener, as Shown in Figure 3.

"The longitudinally arched fastener elements are moved by the slidev in the direction of their arch or curvature whether closing oropening the fastener. f

Iclaim: 1. In a slide fastener, a pair of stringers and fastener elements secured alternately to respectiveV Stringers in predetermined spaced relation .on said stringers, each of said elements having. a

convex and concave' surface of equal radius, the maximum thickness between the curved surfaces being equal to one-third of the said radius, the distance between proximate elements of said Stringer being equal `to one-half of the said radius, the adjacent elements in closed position of the'fastener have a clearance therebetween equal to one-twelfth of said radius, said .clearance permitting a parting movement between stringers limitedby the abutment of the proximate curved surfaces of adjacent fastener ele- Vments,vand each ofsaid elements having means twelfth of the said vradius to Ypermit a, longitudi-V nal displacement between adjacent elements limited'by the abutment of'Y the proximatev curved surfaces of the adjacent fastener elements, each of said 'elements having means to engage Vthe Stringer itv is'. not attached to in the closed positionof thefastener. j

3. In a slide fastener, a pair of stringers and ing the entire length of the element so that the element is arched, the maximum thickness of said arch equals one-third of the said radius, said elements adapted to be superimposed With a clearance between adjacent elements in closed position of the fastener with the convex sides of each element uppermost, said clearance between adjacent elements being equal to one-twelfth of the said radius and permitting a relative movement between the stringers, limited by the abutment of the proximate curved surfaces of the adjacent fastener elements, each of said fastener elements having means, to engage the stringer it is not secured to in the closed position of the fastener. f

4. In a slide fastener, a pair of stringers and arched fastener elements secured alternately to said stringers with one arched end and extending fastener elements secured alternately to each,

Stringer in predetermined spaced relation on the same Stringer, each of said elements having convex and concavesurfaces of equal radius ,extend-` with the other arched end towards the opposite Stringer, the radius of curvature of the surfaces of the arch being equal, and the maximumnthickness of the Varch between the curved surfaces equals one-third of the said radius, said elements being spaced on each Stringer through a distance requal to one-half of said radius to provide a clearance between adjacent elementsv in the closed position of the fastener equal toene-twelfth of said radius to permit a relative movement betweenthe stringers limited bythe abutment of the proximate curved surfaces of g proximate elements, each fastener element having its unconnected end provided with means to engage the Stringer it is not secured to in the closed position of the fastener.

l. -5, In aslide fastener, a pairofstringersand fastener elements secured to each Stringer in predetermined spaced relation, each of said elements having a convex and concave, Surfacev of cylindrical curvature of equal radius extending through the entire length of the element so that Ythe element is arched, the maximum thickness of said -arched plate being equal to @11e-third of the said radius, said elements being spaced on each Stringer to equal one-half of the said radiusto provide a clearance between adjacent curved of said fastener elements having meansV at the unconnected end to engage thejstringer toV 4which itis notsecured. Y Y n y 1 GREGQR RAKOWITZKY.. AReferences cited in the nie of this' patentk VUNITED STATES PATENTS Y v Date 'y Number NameA 1,714,726 Pipes Mayr28',V 1929 1,857,309 Jac0bs1 May 10," 1932 1,864,614 Y Poux June 28, 1932 2,982,619. Dau :June 1,-1937 2,125,698 -Ulbricht Aug. 2, 1938 n FOREIGN `PATEN'rs .Y Number p Country K Date 442,809 Great Britain Ypf 1936Y V615,359 VGreat Britain l o f i949 

